In a song titled "Mr President" released on YouTube, the self-styled cyber freedom fighter, who allegedly masterminded a massive online piracy business, compares himself to US civil rights campaigner Martin Luther King.
Dotcom, free on bail in New Zealand awaiting a US attempt to extradite him for alleged copyright theft, raps "don't vote for those who would take us back in time".
"What about free speech Mr President, what happened to change Mr President," the German national continues in the song, which has attracted almost 500,000 views since it was posted on YouTube on Sunday.
He also complains "Hollywood controls politics" and "the government is killing innovation".
The clip uses footage of civil rights protests from the 1960s as Dotcom sings "I have a dream like Dr King", and more recent pictures of Occupy movement demonstrators wearing Guy Fawkes masks.
A website launched to accompany the song, www.kim.com, features a countdown to the US election in November and asks "if Megaupload.com is not back online by November 1st will you vote for Obama?".